When it comes to decentralized energy production, flexible electricity generation and heat production seem to be mutually exclusive, especially in the case of bio methane CHP plants. The Energielenker from Greven in the Münsterland region show that this is not necessarily the case. Their bio methane CHP plant in tranquil Gronau is an example of this approach – one out of the ten plants currently operated by the Energielenker, which together have a capacity of around five megawatts.
The bio methane plant promoted by the German Renewable Energy Act (EEG) supplies the adjoining disabled facility including the associated workshops and school as well as other local heat consumers such as a swimming pool with about 1.5 GWh of heat per year - a major location advantage for bio methane CHP plants. Since they only require a connection to the gas network, they can also operate without problems in densely populated areas. The required gas, bio methane traded on the balance sheet, is supplied from the natural gas network. Despite the heat supply obligations, they operate the plant not exclusively heat-led, but achieve lucrative additional revenues via a demand-oriented electricity feed-in at the electricity exchange, as Stefan Kienz, product developer at the Energielenker, reports: "The demand-oriented feed-in works without problems. We forecast the heating demand for the upcoming days on a daily basis and use this as a basis for optimizing the CHP schedules. These schedules are sent daily to Next Kraftwerke and the control system of their VPP then remotely ramps our unit up and down according to the schedules."
In addition to providing local heat, the plant, like all other plants in the portfolio of the Energielenker, ensures the stabilization of the German electricity grid by providing and supplying balancing energy via the virtual power plant of Next Kraftwerke. Similar to demand-oriented feed-in, Stefan Kienz's restrictions on heat supply obligations in this market segment are not as far-reaching as it is often assumed. "All our plants have more or less large buffer storage facilities. These facilities enable longer balancing energy activations without any problems. We have already completed one-hour deliveries without any losses in heat supply," Kienz notes. "In the case of very short activations, we don’t have to resort to buffer storage, as heat is a rather inert medium and short-term fluctuations in electricity production are not directly noticeable in heat production." The bio methane plants of the Energielenker offer their capacity primarily in the negative secondary reserve (aFRR), but also the provision of positive secondary reserve is interesting for the Energielenker and should be implemented in the near future.
In this context, Stefan Kienz would like to see more support from the industry on the regulatory and legislative side. "It would certainly have been helpful if the legislator had given the industry clear signals as to how electricity production in the future electricity mix with a considerable proportion of fluctuating feed-in from wind and sun can be adjusted to the electricity demand. At this point, the easily adjustable generation of electricity from combined heat and power (CHP) plays out its full potential - regardless of whether it is operated with natural gas or biomethane. Especially in the current Reneable Energies Act (EEG), dispatchable bioenergy unfortunately does not receive the appreciation it deserves in the German electricity mix." Fortunately, this does not change the fact that bio methane CHP plants, like those of the Energielenker, are already an important cornerstone of the energy system transformation.
Facts & Figures
1.5 GWh per year
Overall portfolio performance:
Direct marketing, balancing energy and demand-driven production